P0443

DTC P0443

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptor
DTC P0443
- Evaporative Emission (EVAP) Purge Solenoid Control Circuit

Diagnostic Fault Information





Circuit/System Description

The EVAP canister purge valve is used to purge fuel vapor from the EVAP canister to the intake manifold. Ignition voltage is supplied directly to the EVAP canister purge solenoid valve. The powertrain control module (PCM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The EVAP canister purge valve is pulse width modulated (PWM). The PCM can determine if the EVAP purge solenoid is operating correctly by monitoring solenoid control circuit voltage and the changes in fuel tank pressure.

The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister purge and vent valves.





Conditions for Running the DTC

* The ignition is ON or the engine is running.
* DTC P0443 runs continuously when the above conditions have been met.

Conditions for Setting the DTC

The PCM detects an incorrect voltage on the EVAP purge solenoid control circuit.

Action Taken When the DTC Sets

DTC P0443 is a Type A DTC.

Conditions for Clearing the DTC

DTC P0443 is a Type A DTC.

Reference Information
Schematic Reference

Engine Controls Schematics ([1][2]Electrical Diagrams)
Description and Operation

Evaporative Emission Control System Description (Evaporative Emission Control System Description)
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information
Special Tools

J-23738-A Vacuum Pump

Circuit/System Verification

1. Command the EVAP purge solenoid ON and OFF with a scan tool. You should hear the solenoid click when commanded ON and OFF.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the EVAP purge solenoid.
2. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 2 and ground.

• If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.

3. Ignition OFF, connect a test lamp between the control circuit terminal 1 and the ignition voltage circuit terminal 2.
4. Ignition ON, command the EVAP purge solenoid ON and OFF with a scan tool. The test lamp should be pulsing ON and OFF when activated.

• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the PCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the PCM.

5. If all circuits test normal, test or replace the EVAP purge solenoid valve.

Component Testing

1. Ignition OFF, disconnect the harness connector at the EVAP purge solenoid.
2. Test for 23-26 ohm at 20°C (68°F) between the control terminal 1 and the ignition voltage terminal 2.

• If not within the specified range, replace the EVAP purge solenoid.

3. Test for infinite resistance between each terminal and the EVAP purge solenoid housing.

• If not the specified value, replace the EVAP purge solenoid.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Evaporative Emission Canister Purge Solenoid Valve Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for control module replacement, setup, and programming